1. Field of the Invention
The present invention relates to a lens-fitted photo film unit, a method of mounting a wrapping on the same, and a method of removing the wrapping from the same. More particularly, the present invention relates to a lens-fitted photo film unit of which a housing has a wrapping disposed thereabout, a method of mounting the wrapping on the same, and a method of removing the wrapping from the same, both in efficient fashion.
2. Description Related to the Prior Art
A lens-fitted photo film unit is known, and disclosed for example in U.S. Pat. No. 5,436,685 (corresponding to JP-A 5-19419). The lens-fitted photo film unit includes a housing, which incorporates a simple shutter mechanism, and is preloaded with unexposed photo film. The housing has a packaging or wrapping disposed thereabout. When a user purchases the lens-fitted photo film unit, he or she can take an exposure readily with it. After taking all exposures on the photo film, the lens-fitted photo film unit can be forwarded to a photofinishing agent without a difficult operation. The lens-fitted photo film unit is commercially marketed in a large scale.
The lens-fitted photo film unit is loaded with the photo film in the course of the manufacture. It is necessary to protect the photo film from moisture before a user actually uses the lens-fitted photo film unit after the manufacture. The lens-fitted photo film unit is firmly wrapped in a water-tight outer packaging bag by a manufacturer, and shipped out. The user tears open the outer packaging bag before he or she uses the lens-fitted photo film unit.
The lens-fitted photo film unit has an advantage of a low cost. To reduce the manufacturing cost, the wrapping to cover the housing consists of a paper box having a decoratively printed surface. The paper box includes six cover regions as rectangular faces and an overlapped region, which in combination constitute one piece of paper. The paper piece is bent straight along each of edges. Also Japanese Utility Model Application No. 3-56924 suggests the lens-fitted photo film unit of which a sheet strip like a belt is used as a wrapping to cover the housing. The sheet strip is wound about the center of the housing. Ends of the sheet strip are attached to one another by virtue of an adhesive agent. Two lateral portions of the housing remain uncovered. This has an advantage in facilitation of assembling operation. Appearance of the lens-fitted photo film unit is also enhanced, as the sheet strip can give a minimized impression to purchasers.
Whichever type of the wrapping is used, the cover regions and the overlapped region are adhered to one another to set the wrapping completely. There is a shortcoming in the wrapping, which is likely to project outwards away from the housing, to render the appearance of the lens-fitted photo film unit remarkably worse. To overcome this shortcoming, Japanese Utility Model Application No. 2-57427 suggests the lens-fitted photo film unit in which the wrapping is directly adhered to the housing for the purpose of tight contact between them.
To attach the wrapping, synthetic adhesive agent, for example, polyvinyl alcohol adhesive agent, is typically used. The adhesive agent essentially consists of synthetic resin as main component, which is resolved with organic solvent. The organic solvent is volatilized to solidify the main synthetic resin. As the outer packaging bag above is used for enclosing the lens-fitted photo film unit, there is a problem due to the organic solvent. When the lens-fitted photo film unit is wrapped without complete volatilization of the organic solvent, organic gas is created, and remains inside the outer packaging bag without dispersion. It is likely that the photo film pre-loaded in the lens-fitted photo film unit is degraded by the organic gas.
To economize natural resources and lessen industrial wastes, there are suggestions of recycling the lens-fitted photo film unit. When a user forwards the lens-fitted photo film unit to a photofinishing agent after exposing the photo film, the lens-fitted photo film unit is collected from the agent to a photo laboratory, where the photo film is removed from the lens-fitted photo film unit and subjected to development and operation of producing photo prints. The lens-fitted photo film unit after the removal of the photo film is withdrawn by the manufacturer. The manufacturer peels the wrapping from the housing, and disassembles the housing into parts. Reusable ones of them are transferred to a manufacturing process, and remounted on a new product. Meltable ones of them are pelleted, and recycled as regenerated material. The wrapping is also recycled in a form of regenerated paper.
For the lens-fitted photo film unit in which the wrapping is directly attached to the housing, the wrapping must be peeled partially by a cutter blade of a specialized shape, and then pulled away manually from the housing, before the wrapping can be removed from the housing according to a known technique. However the wrapping of every product must be individually peeled by manual operation, which is inefficient and inconsistent with a low cost of manufacture.